It is interesting to notice in these last two tables, and the 
remark on Sulphurous acid, the sharp line of demarkation 
between the amount of acid contained in water in which 
life can originate and that which totally prevents origination. 
In the case of Sulphuric acid we find that the small 
amount of 0 010 grins, per litre in addition to the ordinary 
acidity completely prevents it, whilst, in the case ot 
Hydrochloric acid, 0 00-5 grins, per litre is sufficient. In the 
case of Sulphurous acid the author could not get life to 
originate in water containing any of that acid. 
